Your Digest for Sunday, Mar 24, 2024 05:59 PM


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Causes of hemidiaphragmatic elevation

[!INFO] From radiopaedia
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Q 7: Craniopharyngioma


  1. CRH stimulation test - differentiates Cushing's disease from all other causes of hypercortisolism


Folate and B12 metabolism

[[DNAFolateB12Deficiency.png]]
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Source

[!INFO] Key points:

  1. The synthesis of methionine from homocysteine is catalyzed by methionine synthase, an enzyme that requires not only folate (as 5-methyltetrahydrofolate) but also vitamin B12.
  2. 3 vitamins are interlinked : B12, B9 and B6
  3. Thus, the concentration of homocysteine in the blood is regulated by three B-vitamins: folate, vitamin B12, and vitamin B6

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| Folate | B12 |
| :--------------------------------------------------------------------------------------------------------------: | :-------------------------------------------------------------------------------------------------------------------------: |
| green leaves (mnemonic: folate = foliage) | Animal sources |
| 4 months of stores | 2 years of stores |
| large percentage destroyed in cooking | Only little destroyed in cooking |
| Absorption is mainly in the duodenum and jejunum Source | Terminal ileum by receptor mediated endocytosis. Source |


Presentation

Labs:

Management


Urea is elevated in acute dehydration.
Mechanism: Source

[!INFO] Shortcuts


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Side effects of Erythropoietin treatment:

There are a number of reasons why patients may fail to respond to erythropoietin therapy:


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[!INFO] Mnemonic:
Poor penetration : BAT CAVE (deep dark corners = poor penetrance)
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Cephalosporins:


Toxin Antidote
Acetaminophen N-Acetylcysteine
Anticholinergics Physostigmine*
Anticoagulants, oral factor Xa inhibitors (apixaban, edoxaban, rivaroxaban) Andexanet alfa
Benzodiazepines Flumazenil*
Black widow spider bite Lactrodectus antivenom
Botulism Botulinum antitoxin
Beta-blockers Glucagon, IV lipid emulsion
Calcium channel blockers Calcium
IV insulin in high doses with IV glucose
IV lipid emulsion
Carbamates Atropine Pralidoxime chloride
Crotaline snake bites (US) Crotalinae polyvalent immune Fab (ovine)
Cyanide Hydroxocobalamin Cyanide antidote kit (includes amyl nitrate, sodium nitrite, and sodium thiosulfate) Vit B12 forms cyanocobalamin which restores mitochondrial function
Dabigatran Idarucizumab
Digitalis glycosides (eg, digoxin, digitoxin, oleander, foxglove) Digoxin-specific Fab fragments Fab = Antigen binding fragments
Ethylene glycol Fomepizole Ethanol [[2021 General Medicine July#Methanol poisoning]] (alcohol dehydrogenase inhibitor)
Heavy metals Chelating drugs (see table Guidelines for Chelation Therapy) heavy metals: Dimercaprol (aka British anti-lewisite)
Cobalt, Pb, Zn : Edetate calcium sodium
Au,Pb,AS : Penicillamine
Succimer
Ionizing radiation Potassium iodide
Iron Deferoxamine
[[Tuberculosis#Isoniazid|Isoniazid]] Pyridoxine (vitamin B6) Pyridoxine (B6)
Methanol Fomepizole Ethanol Prevents formation of glycolic acid and glycloxylic acid by alcohol dehydrogenase.
Methemoglobin-forming agents (eg, aniline dyes, some local anesthetics, nitrates, nitrites, phenacetin, sulfonamides, dapsone). Methylene blue
Exchange transfusion
Hyperbaric oxygen
Hb has Fe3+ instead of 2+. (poor O2 capacity).
Blue Skin.
Dark blood.
Methotrexate Leucovorin (folinic acid) Glucarpidase (carboxypeptidase-G2)
Opioids Naloxone
Organophosphates Atropine, Pralidoxime See above
Scorpion envenomation (Centruroides sp) Centruroides immune F(ab’)2
Sulfonylurea Octreotide Somatostatin analog; prevents calcium entry into beta cells -> inhibits insulin release. Prevents rebound hypoglycemia in sulfonylurea overdose.
Thallium Prussian blue
Tricyclic antidepressants Sodium bicarbonate
Unfractionated heparin Protamine
Valproic acid L-Carnitine†
Warfarin Vitamin K
Fresh frozen plasma Prothrombin complex concentrate (PCC)

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#2021BSQ-NOV/Q54
Aporecaeruloplasmin + 6 Cu atoms = ceruloplasmin (the major circulating form of Copper)

Mutations in ATP7B in Wilson disease impairs both the incorporation of copper into apoceruloplasmin and the excretion of copper into bile.

[!TIP] Eyes and basal ganglia and of course liver


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Source
Foscarnet and cidofovir are toxic.

Source

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See [[Anaemia#Folate and B12 metabolism]]
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